54 national geographic • August 2016
California, Berkeley, where she is professor
of chemistry and molecular biology. In 2012,
Doudna and her French colleague Emmanuelle
Charpentier were the first to demonstrate that
scientists could use CRISPR to edit purified
DNA in lab dishes. “I don’t know that we know
enough about the human genome, or maybe any
other genome, to fully answer that question.
But people will use the technology whether we
know enough about it or not.”
The more rapidly science propels humanity
forward, the more frightening it seems. This
has always been true. Do-it-yourself biology is
already a reality; soon it will almost certainly
be possible to experiment with a CRISPR kit
in the same way that previous generations of
garage-based tinkerers played with ham radios
or rudimentary computers. It makes sense to be
apprehensive about the prospect of amateurs
using tools that can alter the fundamental ge-
netics of plants and animals.
But the benefits of these tools are also real,
and so are the risks of ignoring them. Mosqui-
toes cause immense agony throughout the world
every year, and eradicating malaria or another
says. “Avian malaria is destroying the wildlife
of Hawaii, and there is a way to stop it. Are we
really willing to just sit there and watch?”
In February of this year, U.S. Director of
National Intelligence James Clapper warned
in his annual report to the Senate that tech-
nologies like CRISPR ought to be regarded as
possible weapons of mass destruction. Many
scientists considered the comments unfounded,
or at least a bit extreme. There are easier ways
for terrorists to attack people than to conjure up
new crop plagues or deadly viruses.
Nevertheless, it would be shortsighted to
pretend that the possibility for harm (includ-
ing, and perhaps especially, accidental harm)
does not exist with these new molecular tools.
The scientists most responsible for advances
like CRISPR agree that when we begin to tinker
with the genetic heritage of other species, not
to mention our own, it may not be easy, or even
possible, to turn back.
“ What are the unintended consequences
of genome editing?” asked Jennifer Doudna,
as we spoke in her office at the University of
ALTERED
GENE
WILD
ALTERED
GENE
WILD
ALTERED
GENE
WILD
EDITED
SECTION
CRISPR
Most genes in a species have
a one-in-two chance of being
inherited by each offspring.
But with the advent of CRISPR
and a controversial technique
called engineered gene drive,
scientists are beating those odds
in the lab. An alteration that makes
a mosquito resistant to malaria,
for example, can be engineered
to be inherited by all its offspring.
Spreading
the Cure
Natural process
A gene is typically inherited by its
offspring about 50 percent of the time.